Functional characterization of serine proteinase inhibitor Kazal-Type in the red claw crayfish Cherax quadricarinatus.

Serine protease inhibitors Kazal type (SPINKs) function in physiological and immunological processes across multicellular organisms. In the present study, we identified a SPINK gene, designated as CqSPINK, in the red claw crayfish Cherax quadricarinatus, which is the ortholog of human SPINK5. The deduced CqSPINK contains two Kazal domains consisting of 45 amino acid residues with a typical signature motif C-X-C-X-PVCG-X-Y-X-C-X-C-X-C.

Comparative study of five anti-lipopolysaccharide factor genes in Litopenaeus vannamei.

Anti-lipopolysaccharide factors (ALFs) are a family of common innate immune effectors in crustaceans, and they exhibit broad spectrum antimicrobial activity. In this study, we identified and characterized five novel ALF genes (designated as LvALF1-5) from the Pacific white shrimp (Litopenaeus vannamei) to investigate their potential immune functions. The amino acid sequence alignments showed that LvALFs contained two conserved cysteine residues, a hydrophobic N-terminal region, and the conserved signature sequence W(T/K)CPG(S)WT(A).